A motor of this kind is disclosed in, for example, Japanese Utility Model Laid-Open No. 2551167. The motor disclosed in Japanese Utility Model Laid-Open No. 2551167 is made up of a stator 52 fixed to a base 51 as a non-rotating portion and a rotor 53 rotating integrally with a rotating shaft as a rotating portion as shown in FIG. 10. The stator 52 has a bearing 54 and a bearing housing 55, a core 56 having a salient pole, and a coil 57 wound around the salient pole of the core 56. The rotor 53 has driving magnets 58 made up of permanent magnets which are coaxially disposed on an inner periphery of a hub (rotor case) 59 holding a disk and opposite the core 56 across a small gap so that N poles and S poles are alternately arranged in a circumferential direction. In FIG. 10, a part of the base 51 constitutes the bearing housing 55, which is shaped like an upright cylinder.
As shown in FIGS. 10 and 11A, an insulating sheet 60 is provided on a motor-interior-side surface of the base 51. A flexible printed circuit board (FPC) 61 is provided on a motor-exterior-side surface of the base 51. Holes 51a, 60a, and 61a that are in communication with one another are formed in the base 51, the insulating sheet 60, and the flexible printed circuit board 61, respectively. Leads 57a of the coil 57 are led out of the motor through the holes 51a, 60a, and 61a. The leads 57a are connected to respective lands formed on the flexible printed circuit board 61 with a solder 62. In general, the diameter d1 of the hole 60a, formed in the insulating sheet 60, is as large as the diameter d2 of the hole 61a, formed in the flexible printed circuit board 61 and is smaller than the diameter d3 of the hole 51a, formed in the base 51. This configuration allows the regulation of the positions of the leads 57a of the coil 57 inserted through the holes 51a, 60a, and 61a by the hole 60a of the insulating sheet 60 and the hole 61a of the flexible printed circuit board 61, preventing the leads 57a from contacting an inner peripheral wall surface of the hole 51a in the base 51. This maintains the insulation (an appropriate breakdown voltage) between each of the leads 57a of the coil 57 and the base 51.
However, in the above-described conventional configuration, the diameter d1 of the hole 60a in the insulating sheet 60 and the diameter d2 of the hole 61a in the flexible printed circuit board 61 are both small. Drawing out the leads 57a of the coil 57 is thus difficult. In particular, it is very difficult to lead the lead 57a of the coil 57 through the hole 61a in the flexible printed circuit board 61, which is located inside when the lead 57a is drawn out of the motor. Thus, disadvantageously, the lead 57a of the coil 57 may be entangled inside the hole 51a in the base 51 as shown in FIG. 11B.
To solve this problem, Japanese Patent Laid-Open No. 2005-210787 proposes a motor in which the diameter d11 of a hole 71a in a flexible printed circuit board 71 and the diameter d12 of a hole 72a in an insulating sheet 72 are both set smaller than the diameter d13 of a hole 73a in a base 73 and in which the diameter d11 of the hole 71a in the flexible printed circuit board 71 is set greater than the diameter d12 of the hole 72a in the insulating sheet 72 as shown in FIG. 12.
With this configuration, when drawing out leads 74a of a coil 74, the same can be easily led through the hole 71a in the flexible printed circuit board 71, located inside. This makes it possible to prevent the leads 74a of the coil 74 from being disadvantageously entangled inside the hole 73a in the base 73.
Japanese Patent Laid-Open No. 2000-209804 proposes a motor having a substantially V-shaped guide portion 83 formed in a flexible printed circuit board 81 so that leads 82 of a coil can be guided through the guide portion 83, and a cut 85 formed in the flexible printed circuit board 81 so as to allow the guide portion 83 to communicate with a coil insertion hole 84 through which the leads 82 of the coil are led as shown in FIG. 13. The coil insertion hole 84 is formed at a position where in a plan view, the coil insertion hole 84 appears to overlap a central part of a hole 86 in a base. The guide portion 83 of the flexible printed circuit board 81 is formed at a position such that the guide portion 83 is finally located outside the hole 86 in the base, that is, such that the guide portion 83 finally overlaps a motor-exterior-side surface of the base.
This configuration allows the leads 82 of the coil to be easily drawn out to an area close to the center of the hole 86 in the base without contacting a peripheral surface constituting the hole 86 in the base.
However, in the configuration disclosed in Japanese Patent Laid-Open No. 2005-210787, the interior of the hole 73a in the base 73 and the interior of the hole 71a in the flexible printed circuit board 71 are hollow. Thus, disadvantageously, the leads 74a of the coil 74 are not held in the holes 73a and 71a and are thus unstable. To eliminate this disadvantage, a resin such as an adhesive may be poured into the hole 73a in the base 73 to fix the leads 74a. In this case, the resin may leak out of the hole 71a in the flexible printed circuit board 71 or the hole 72a in the insulating sheet 72 (in particular, when the resin is poured into the hole 72a in the insulating sheet 72, the resin is likely to leak out of the hole 71a in the flexible printed circuit board 71). This prevents the leads 74a from being appropriately fixed.
In contrast, with the configuration disclosed in Japanese Patent Laid-Open No. 2000-209804, when the diameter of the coil insertion hole 84, through which the leads 82 of the coil are lead, corresponds to the number or size of the leads 82 led through the coil insertion hole 84, the resin can be prevented from flowing out of the hole 86 in the base. However, in the configuration, the substantially V-shaped guide portion 83, through which the leads 82 of the coil are guided, is formed by notching the flexible printed circuit board 81. Consequently, when the flexible printed circuit board 81 is stuck to a sticking surface of the base (the motor-exterior-side surface of the motor), only the notch portion in which the guide portion 83 is formed has a smaller sticking area. Thus, disadvantageously, the flexible printed circuit board 81 easily peels off the sticking surface in the notch portion.
Furthermore, the configuration disclosed in Japanese Patent Laid-Open No. 2000-209804 requires the following operation. With the flexible printed circuit board 81 not stuck to the motor-exterior-side surface of the base yet, the leads 82 of the coil are led through the hole in the insulating sheet stuck to the motor-interior-side surface of the base. The flexible printed circuit board 81 is then moved so that the leads 82 of the coil are inserted into the coil insertion hole 84 via the guide portion 83 in the flexible printed circuit board 81. The flexible printed circuit board 81 is further stuck to the base. This operation disadvantageously requires much time and effort, resulting in degraded workability.